<TITLE>WWX_BOF_mins -- /IETF92</TITLE>
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<H1>WAIS-W3-x.500 BOF Minutes</H1>BOF at the March 1992 <A NAME=4 HREF=IETF-9203.html>IETF</A> , on the evening of March 18.
<H2>Summary</H2>This meeting followed discussion at the <A NAME=7 HREF=LivingDocuments.html>"living documents" BOF</A> the
previous evening, and was more focussed in its discussion.<P>
The WAIS, World-Wide Web, Prospero systems for network information
retrieval (NIR) were presented (the Gopher protocol was presented
in plenary the following day).  The x500 directory was presented in
the light of NIR needs, as were two proposals to use the directory
to refer to documents. A discussion followed as to how to allow these
systems to inter-operate, and on requirements for name spaces. A working
group was proposed to define the format for a generalized printable
format for a name or address in any of these systems.
<DL>
<DT>Chair
<DD> Steve Kille, UCL and  ISODE consortium
<DT>Present
<DD> See list <A NAME=3 HREF=../../WWW/Administration/Mailing/ietf-wwx-bof>ietf-wwx-bof@info.cern.ch</A> .
</DL>
These minutes are available in hypertext form using WWW as	http://info.cern.ch./hypertext/Conferences/IETF92/WWX_BOF_mins.html
as well as through the normal channels.
<H2>WAIS</H2>John Curran of BBN presented the WAIS protocol, in the absence of
anyone from Thinking Machines Corporation who were originally responsible
for it.  The WAIS model is of a number of servers, each of which serves
a number of databases, each of which contains a number of documents.
 Client software allows many databases to be searched at the same
time.  The server keeps an inverted full text index for each database,
so the search is very fast.  Non-text files may also be served: recent
extensions allow indexing of text files in new formats.  The files
indexed need not be copied, but the index is of the same order of
size as the files.<P>
Many databases exist, but there is no scalable way of finding them
(TMC currently keeps a master index). Use of x500 was discussed.<P>
The WAIS protocol is an extended subset of Z3950. The differences
were discussed:  WAIS allows relevance feedback ("Give me a document
like this one") , and  specifies how a query should be formulated.
 WAIS and Z39.50 have the same presentation layer. 
<H2>Documents in the Directory</H2>Wengiyk Yeongpresented his paper OSI-DS-22, <A NAME=9 HREF=//uu.psi.com/wp/nir.txt>"Representing public archives in the
directory"</A>. His project puts information about documents, including
the network address for retrieval, into the directory. He currently
has RFCs and FYI documents in, but would like to move on to other
internet archives.  He concluded that he needed a more sophisticated
approach. It was difficult to characterize arbitrary archives, with
too little information about them. (See <A NAME=10 HREF=IAFA-BOF.html>IAFA WG</A>).
<H2>The World-Wide Web</H2>Tim Berners-Lee presented the World Wide Web (w3) and discussed requirements
for interworking between the systems.  The W3 project was initially
funded to provide an information infrastructure to the world-wide
community of high energy physicists.  The data model is of documents
which are hypertext and/or searchable indexes.  The philosophy behind
it is that a user should be able to point and click on phrase or a
word within a document and the associated document would be retrieved
from wherever in the world and presented to the user in an appropriate
format - without the user having to be aware of where the document
is located or what the access method is.  These details are hidden
in the hypertext links.  There were server programs for many information
servers, gateways to WAIS, Archie and gopher and client programs for
various user machines.  <P>
The W3 clients use several protocols for accessing documents (FTP,
NNTP, WAIS, Gopher, and W3's own "HTTP") although this is hidden from
the user. The HTTP protocol is a simple stateless search/retrieve
protocol running over TCP.  As originally conceived but not yet implemented,
it included authentication and data format negotiation.Tim discussed the differences between WWW, WAIS, Archie, Gopher and
Prospero systems.<P>
The need for a  Universal Document Identifier (UDI) for describing
the address or, given a directory, name, for a document whatever is
access protocol was discussed, as outlined in OSI-DS-XX.  Each application
 uses a "handle" for a file which can be prefixed by the particular
protocol name to generate a universal address. <P>
Most systems (WAIS excepted) are extensible, entertaining document
addresses which refer to other systems.  WAIS indexes currently can
only refer to documents in the same database, let alone with other
retrieval methods. There is a need for WAIS to be more flexible. John
Curran said he would bring this to the attention of the WAIS community.<P>
Addresses would not in the long term be suitable for references to
documents, so it was hoped that some sort of directory service, operating
within the UDI framework, would be incorporated.<P>
More information:	telnet info.cern.ch.   Client and server code is
available by anonymous FTP from info.cern.ch.<P>
Mailing lists:  www-talk@info.cern.ch, www-interest@info.cern.ch<P>
Discussion document:   <A NAME=11 HREF=//cs.ucl.ac.uk/osi-ds/osi-ds-29-00.txt>OSI-DS-29</A>
<H2>Representing the Real World in the Directory</H2>Paper: <A NAME=12 HREF=//cs.ucl.ac.uk/osi-ds/osi-ds-25-00.txt>OSI-DS-25</A>Steve Kille discussed this paper "Representing the Real World in an
X.500 Directory".<P>
A Listing Service may be used to group like information items together
for example to provide a Yellow Pages Service.<P>
Such a service could for example provide for members of a special
interest group, or could group documents on a particular subject.Services such as Archie could be considered to be Listing Services.
One imagines an information Universe in which Information Brokers
provide different subject based (say) views via their listing service.
One would then need to locate the various listing services (using
a mechanism such as a directory?) 
<H2>UK British Library Project</H2>Paul Barker described a project, sponsored by the British Library,
to represent grey literature (unpublished research papers) in the
Directory.  The project is thought to be unlikely to succeed - but
one of the aims is to demonstrate whether or not it is possible. 
They will take the (UK) MARC records and model these within X.500.
 They might also consider trying to provide a listing service so that
the documents might be retrieved more readily by subject area.
<H2>Prospero</H2>Cliff Neuman described Prospero.  It follows a file system model,
rather than the hypertext model.  It is built on UDP for speed.  It
has the notion of a Directory which contains links to other objects
(other directories or files).  It returns the link to the information
object and then automatically retrieves the file by another mechanism
by the appropriate access method (Archie, WAIS, nntp, WWW - soon!,
NFS, ftp etc.) It has been used very successfully to access the archie
database. <P>
Cliff stated that he expected to be able to use X.500 to translate
between the document ID and how to get the document.<P>
With Prospero the user has his own view of the global information
base (or has a view built for him).  Cliff thought there should be
multiple name spaces - but the difficulty would be that these would
need representing near the top of the directory tree.  With multiple
user chosen views - this would be difficult to manage.  Also two users
might refer to an object by different handles which would be relative
to their individual name spaces - difficult when passing references
(say in a mail message) from one person to the other.<P>
The concept of "Closure":  Each object has a related name space. All
references within the object are resolved using the context of the
name space. Name spaces themselves have global network addresses,
but the user doesn't see that. <P>
More information:  info-prospero@isi.edu
<XMP> 
</XMP>
<H2>System 33</H2>Larry Masinter talked about a project at Xerox PARC. This has the
concepts:
<DL>
<DT>HANDLE
<DD>32 byte number (is a content ID). In fact this contains hints
for finding the document.
<DT>FILE Location  (6 part)
<DD> Protocol; Host; Path; piece; format; timeout
<DT>Description
<DD> (normal "Catalogue" information: Name, Author, etc) 
</DL>
There is format negotiation when a document is retrieved. It is not
simple in reality to categorize data formats as there is such a plethora
of different varieties.<P>
Gateways provide access between systems not sharing transport protocols.<P>
Also considered Access Control.  ACL is part of description.  The
Server exploits multiple protocols for Search and retrieve.<P>
There is a problem with dealing with different types of document (applications
for jobs, product specs, memos, contracts, faxes, etc. ) It is difficult
to normalize the attributes of a general document.
<H2>Summing up</H2>Tim Berners-Lee summed up by saying that all applications described
used resolvable document address, and so for interworking, we need
a universal representation for such a network object address. With
the coming of  directories, names should increasingly be used in place
of network addresses. The Universal Document Identifier was intended
to be able to hold either an name or address for any access protocol.
 (This is not the same as "USDN" a document serial  number which is
not resolvable, but only one of which exists for each document). <P>
 In discussion, Steve Kille suggested should be a WG on details of
UDIs  and a separate one for USDN.  A comment was that the W3 data
model encompasses those of the other systems.    John Curran insisted
on a better term than "UDI", suggesting "Document Access Token". <P>
Peter Deutch's need for a USDN is to be able to determine the equivalence
of two USDN. Chris Weider agreed to co-author a document on the issues.
Jill Foster suggested a pilotproject to put UDI's in the directory for a set of documents and to
have the gopher, Prospero, archie, and Prospero people try to utilise
these.[These minutes have been largely built from Jill Foster's <A NAME=5 HREF=WWX_BOF.html>report</A> and
Karen Sollins' <A NAME=8 HREF=WWX_BOF_Sollins.html>notes</A> for which I am most grateful, though errors in
the above are probably mine. <A NAME=0 HREF=http://info.cern.ch./hypertext/TBL_Disclaimer.html>Tim BL]</A></A>